Knee arthroscopy is one of the common procedures performed in orthopaedic for a variety of pathologies. It is a safe day case procedure with relatively few complications. We report a case of extravasation of fluid into the anterior thigh compartment during a routine arthroscopic procedure for a symptomatic lateral meniscus tear. This was potentially due to a breach in the superior capsule causing fluid extravasation in the thigh compartment.
Knee arthroscopy is one of the commonly performed day surgery procedure in orthopaedic with low complications rates of 0.27% (1). Data from the English NHS patients has shown that approximately 301,701 arthroscopic operations were performed between 2005 and 2010 – an annual incidence of 9.9 per 10,000 of the English population. Thirty-five percent of these were for meniscal surgery (2). The reported incidence of increased thigh compartment pressure secondary to extravasation of fluid during knee arthroscopy is extremely low (3). We report a case of thigh fluid extravasation which occurred during a routine knee arthroscopy procedure performed by an experienced surgeon. We present our management strategy employing a multi-professional approach and discuss the relevance and importance of the professional duty of candour to this patient’s care.
A 59-year-old female patient was referred to us with 12 months’ history of increasing knee pain following a twisting injury. She presented with pain and mechanical symptoms of clicking, locking and giving way. Following an unsuccessful course of physiotherapy treatment, she was scheduled for knee arthroscopy with a clinical and radiological diagnosis of a lateral meniscal tear.
The procedure was carried out under general anaesthesia. A proximal thigh tourniquet was used at a pressure of 300 millimetres of mercury (mmHg). The arthroscopy pump used was Arthrex Continuous Wave III with pressure of 50 mm Hg and flow rate of 70%. Medical suction was used with the shaver with pressure of 50 kiloPascals (kPa). Normal saline was the irrigation fluid used. Joint exploration revealed a tear of the lateral meniscus which was debrided using a shaver. Outerbridge grade 2 cartilage damage was found in the weight bearing portion of medial and lateral condyles of the femur and tibia. The tourniquet time for the procedure was 26 minutes. No technical difficulties were encountered. After the removal of the drapes and tourniquet significant thigh swelling was noted extending from the knee up to the distal extent of the tourniquet. The anterior and medial thigh compartments were firm to palpation and pulses were normal distally. These findings led to a concern about compartment syndrome.
A pressure transducer was assembled using the anaesthetic monitoring equipment. This was done by the anaesthetist and was used to measure the compartment pressure which was found to be 28 mmHg in the anterior, 18 mm Hg in the medial and 0 mmHg in the posterior compartment (normal pressures 0-5mmHg). The difference between the compartment pressure and the mean arterial pressure was >30mm Hg hence decompression was not carried out. No motor or sensory neurological deficits were noted. The opinion of a senior orthopaedic surgeon was sought as well.
The patient was closely monitored on the ward by nursing and physiotherapy staff. Analgesic requirement, calf girth measurement and neurovascular observations were carefully documented. She was admitted for overnight monitoring.
Once she had fully recovered from the anaesthetic the surgeon reviewed her and explained the findings of the procedure as well as the findings in her thigh immediately following the procedure. The clinical findings, their implications, the potential consequences of compartment syndrome as well as the steps taken to rule this out were carefully explained and documented. The techniques used for monitoring and the reason for her prolonged admission (given that a knee arthroscopy is usually a day case procedure) were clearly explained.
A multi-disciplinary approach to the patient’s care was undertaken with involvement of the orthopaedic surgeons, intensivist, physiotherapist and pain management team. The patient recovered well and was discharged home after 3 days with community based physiotherapy. 6 months following the procedure, the patient has regained full knee range of movement with no long-term consequences.
Knee arthroscopy is a safe, often day surgery procedure with a very low incidence of adverse events (1). Complication rates reported in literature include readmission wound problems (0.64%), re-operation (0.42%), 30-day readmission (0.64%), 90-day Pulmonary embolism (0.08%) and 90-day mortality (0.02%) rates (2). Rare complications include septic arthritis (<1%) (4), venous thromboembolism (2.8 cases of PE for every 10,000 arthroscopies) (5), (6), extravasation of the fluid in the limb leading to potential compartment syndrome (3), (7-12), neurovascular injury (13-18), arthrofibrosis(19), broken or detached instruments requiring reoperations for retrieval (20-23), chondral injury (24), subchondral fracture25,chondrolysis (26) and osteonecrosis (27). The incidence of the complications in these reports were related to the complexity of the case and length of surgery.
Extravasation of fluid in the leg has been reported associated with knee arthroscopy when combined with other procedures such as High tibial osteotomy (7) and tibial plateau fracture fixation (9). This carries a risk of compartment syndrome (28). Far fewer have been associated with partial meniscectomy and even fewer cases in which fluid extravasated into the thigh. Proposed mechanisms include capsular breach (28), fault in the pressure sensor (3) or high pressure setting for the arthroscopy pump (11) have been implicated. Bomberg et al (28) reported 1.4% complication rate of fluid extravasation in the initial phase of the use of an infusion pump causing compartment syndrome in the leg (1 case requiring fasciotomy) and thigh (3 cases, 1 requiring fasciotomy. Cavaignac et al (3) reported a case of fluid extravasation in the thigh up to the groin during ACL reconstruction which was thought to have occurred due to a faulty pressure sensor and was managed conservatively. A similar cause was reported by Romero et al (11). Extravasation of the fluid causing swelling of the groin, penis and scrotum with massive intraperitoneal and extra-peritoneal fluid accumulation with no evidence of compartment syndrome. In our case, though the fluid accumulation was limited to the thigh compartment up to the groin. This was managed conservatively with no further sequelae.
To the authors’ knowledge there has been no discussion of the importance of the duty of candour of the treating physician to the patient or the absolute importance of discussing the complications as well as associated issues with the patient. Neither has the importance of regular review and support provided by the multidisciplinary team. In this case the presence of clinicians of differing specialities as well as allied professionals contributed to an accurate, timely diagnosis of a very unusual presentation, monitoring, rehabilitation and recovery of the patient.
In prolonged cases or surgeries with potential for fluid extravasation, the surgeon should be extremely vigilant to minimise the risk of this complication. Regular check on the pump pressure, fluid input/output and clinical assessment for tight compartments should be routine practice. A clear honest discussion with the patient is mandatory to inform them and involve them in their management and care should be provided by a multi-disciplinary team approach in order to optimise the clinical outcome. This case also highlights the importance of the professional duty of candour (29) in the patient care when an unexpected event occurs which has potential to cause harm or distress.